Is a tele-compressor causing this?

[jimmy10fingers]

Hi everybody,

As part of my astro project, I have taken a series of images the recent SN2011fe. Unfortunately, the stars in the image appear skewed as if the scope was moving very slightly. It was not however, as the skews are not all in the same direction. Instead the skews are radial, so two stars on opposite sides of the image are skewed in opposite directions.

Now, I don't have much practical experience with telescopes but even my supervisor doesn't really know what is causing it. I spoke to the technician and he said it was possibly the tele-compressor we were using, although he hasn't seen the image.

Does anyone know if the tele-compressor could have caused this and how it caused it. Also is there a possible way to correct the image, as it would make photometry a lot easier!

Thanks

jimmy10fingers

PS, not sure if its right to start a new thread asking this, but forgive and correct me if ive posted in the wrong place

[rfdesigner]

Sounds like you're guiding and have the scope out of alignement. In this case the sky will rotate around the guide star... very common if you're not correctly aligned.

So.... did you guide?.. did you take long images or short ones.. did you carefully align the mount... or are you using an 'alt-az' mount rather than an 'equitorial mount' either a fork on a wedge or a german equitorial?

Edit: looking again.. it's not that bad.. perhaps a bit of coma at the edge of the field, and a touch out of focus.

Derek